Presses, moldings and forming machines



Aug. 4, 1964 v M. MAZZONI v PRESSES, MoLDINGs AND FoRuING MACHINES 2 Sheets-Sheet 1 Filed July 18. 1961 lnk MAP/a /I//Azzo/v/ 00m., y. M

AUS- 4, 1964 M. MAzzoNl 3,142,863

PRESSES, MOLDINGS AND FORMING MACHINES Filed July 18, 1961 2 Sheets-Sheet 2 /lv vE/vroR MAP/0 /WZZU/w By M United States Patent O 3,142,863 PRESSES, MLDINGS AND FRMING MACHINES Mario Mazzoni, Busto Arsizio, Italy, assigner to G. Mazzoni S.p.A. Filed July 18, 1961, Ser. No. 124,980 Claims priority, application Italy Aug. 1, 1960 6 Claims. (Cl. 18-2) When forming substances having plastic consistency, such, for example, as soap, margarine, and the like into an oval, elliptical, spherical, or tapered pyramidal shape, with sharply rounded surfaces, or into any other shape (similar to fruits, animals, stars, flowers, and the like) not having flat side bands, machines are generally used which are hand-operated, pedal-operated, semi-automatic or automatic, being provided with two-piece dies or molds (moving and stationary) suitable for giving the finished piece its final desired shape.

The edges of the moving and stationary dies match up perfectly with one another. Normally the blank piece fed to the dies has a volume 10% to 30% greater than that of the stamped product.

Therefore, during the pressing operation, that is, on the closing stroke when the two dies are brought together, all the excess material above that contained between the two closed dies and representing the final volume of the finished piece, will be expelled when the two edges of the dies match up perfectly.

An examination ofthe machines which have been built to date to achieve the above purpose and, in particular, taking into consideration the machines which work fully automatically, one finds above all else the following disadvantages:

(1) Difficulty in reaching high stamping speed and, along with it, a high hourly output.

(2) Difficulty in detaching or stripping off the excess scrap material expelled from the dies.

(3) Difficulty in detaching the molded product from the inner surfaces of the dies.

The improvements in and to such machinery embodied in the invention have as their object the elimination of the above mentioned difficulties.

In order to attain a high hourly output and still keep the molding speed within reasonable limits, the press, molding or forming machine embodied in the invention has several sets of dies enabling it to simultaneously press a number of finished pieces for each single closing stroke of the machine.

In order to be able to feed the machine automatically and thus install it in a continuous processing line (for example, for the production of the toilet soap) together with other machines such as mixers, extruders, automatic cutters, cooling tunnels, etc. the press has been coupled with a feed device which, receiving the pieces to be pressed on a single, central conveyor belt, distributes them automatically to one or more side conveyors, each arranged to line up with one set of dies.

A gripper device located at each feed conveyor belt picks up, the piece of the product on each belt and places it in perfect timing, between the corresponding set of dies (moving die and stationary die) in preparation for the successive molding.

The fixed, or stationary dies are rigidly anchored to the body of the press and therefore do not move in any way. The moving dies are fixed to a slide which has a reciprocating vertical motion provided by a suitable mechanism of known type.

Each time the slide carrying the moving die or dies moves downwards a molding stroke is made,

The motion of the feed grippers supplying the pieces to be molded is suitably synchronized by means of cams with the motion of the moving dies.

ICC

During the molding cycle the excess material in respect to the volume contained bet-Ween the moving and stationary dies is expelled.

In the machine embodied in the invention, in order to obtain a clean, thorough stripping off of the excess material expelled from the dies, the dies have a peripheral cutting edge which follows exactly the outline of the shape of the piece of material being molded and thus, too, the outer surface of the moving and fixed dies completely follows the outline of the molded piece.

A trimming ring is mounted around each moving die, which ring is free to move or slide, but in close contact with the outer surface of the moving die. During the molding stroke said ring is held away at a distance from ythe level of the cutting surfaces of the moving die. Immediately after the molding stroke, that is, `after the excess material has been completely expelled, just as the moving die starts its opening stroke away from the stationary die, said trimming ring suddenly shifts its position to beyond the level of the cutting surfaces of the fixed die and cleanly cuts off all the excess material which has come out of the dies, after which the trimming ring withdraws, moving away from the level of the cutting surfaces of the fixed die and following the motion of the moving die around which it is placed.

In order to ensure that the trimming ring comes into action very quickly, this ring, as in one of the preferred embodiments of the invention, is fixed to the end of a rod connected to the piston in an air cylinder operated by compressed air through a solenoid valve controlled system, actuated by any suitable system of switches and cams.

After the molding and cutting off of the excess material, it may also happen that the stamped piece remain stuck to the moving die instead of the stationary die as called for in the operating cycle of 4the press, molding or forming machine.

Therefore, the inside of each moving die houses an ejector, the periphery of which usually corresponds to the outline of the engraving to be made in the stamped piece.

This ejector acts after the trimming ring, that is, after the moving die has withdrawn several millimeters distance away from the stationary die. This ejector can be made to operate by means of any type of system, electric, pneumatic or hydraulic. The pneumatic system is to be preferred rto obtain quick action and, using this system, the ejector is driven directly by an air cylinder, operated by compressed air through a system of solenoid valves, actuated, in turn, by any suitable system.

After the stamping and trimming strokes to remove the excess material, the stamped pieces, properly trimmed, re-

main held in the stationary dies.

v An arm, having at its end a suction cup made of rubber or other suitable material, with suitable mechanism for same, moves so as to cause the suction cup to come to rest on the molded pieces, there being a separate arm and suction cup for each piece molded simultaneously. Each suction cup is connected through a suitable circuit to a tank or chamber which is kept under vacuum by a vacuum pump of any known type.

A slide valve, which is operated by its own cam, said When the stamped pieces come to a position exactlyI aleaaea above the discharge conveyor belt, the slide Valve cuts off the connection between the suction cups and the vacuum tank and simultaneously connects the suction cups with the compressed air circuit. The pieces of the product are thus instantaneously detached from the suction cups and are placed on the discharge conveyor belt. This belt should, preferably, be lined with a layer of sponge rubber or synthetic spongy material or other suitable mate rial to keep the molded finished pieces which are detached from the suction cups from being damaged.

The use of compressed air for detaching the pieces from the suction cups is very important in order to ensure that the pressed pieces will be deposited safely and instantaneously on the discharge conveyor belt, even when the machine is running at high speed.

Without the help of the compressed air, which is to say, using only atmospheric pressure, the pieces are deposited irregularly on the discharge conveyor and they do not become detached quickly enough if the machine is running at high speed.

The improvement attained with the use of compressed air is thus evident.

Two forms embodying the improvements in and to presses, molding and forming machines according to this invention are shown in the accompanying drawings as a non-restrictive example, suitable for molding bars of soap, wherein:

FG. l is a vertical section of a device for molding only one bar of soap at a time;

FIG. 2 is a vertical section of a device for molding two bars of soap simultaneously.

The device comprises slide 2 having a vertical, reciprocating motion and carrying moving die 3 supported by support 4 through plate 25.

Fixed die 6 is anchored to base 8.

Slide 2 has mounted to it the air cylinder 9 which has an opening for the passage of compressed air serving as an inlet 10 and another opening serving as an outlet 11, for discharging the air.

Piston or plunger 12 slides inside air cylinder 9 and plunger rod 13, surrounded by spring 13 is fixed to plate 23.

This plate 23 through two rods 22 is united with the trimming ring 15 which slides on the moving die 3, the latter carrying an ejector plunger in line with the axis of said moving die 3, said ejector 2t) being united through rod 19 with drive piston 18, the latter two being located in an air chamber 17 built into the body of the plate 25. Rods 22 slide inside bearings 24 of the fixed plate 2S.

The device for ejection and removal of the finished piece is constructed by means of an air tank, not shown, which supplies compressed air by way of line 26, While line 27 is connected to another tank inside of which a vacuum is maintained by suitable means; said lines are connected to a slide valve 28 of known type, actuated by cam 29. By way of flexible tube 30 and rigid tube 30 the suction cup 31 which is carried by swing arm 32 to the position shown in FIG. 1 in dotted lines, sucks up finished piece P from the fixed die 6, reverses its position shown by the arrows F and F' and returns to the position at which the piece is released, shown in FIG. l in solid lines; due to the contrary effect of the air, controlled by valve 28, piece P falls onto a conveyor belt 33 which carries it to the succeeding steps in the nishing process.

The operation is carried out in the following manner: the machine sets itself up in the position shown in solid lines in FIG. l and while moving die 3 is raised, fixed die 6 is free, the portion of material to be molded being deposited on the latter 6. Next slide 2 moves down, bringing along with it the moving die 3 which is carried down to the point where it matches up with fixed die 6, giving form or shape P to the block of material inside it. Immediately afterwards, compressed air enters cylinder 9, through opening 10, plunger 12 is lowered With plate 23,

moving the rods 22 and trimming ring 15, relative to die 3, which cuts away the excess material which has been forced out of the dies. Then, while die 3 is raised up, compressed air enters the second cylinder 17 through opening 34 to lower plunger 18 and with it the ejector or knockout 2t), which causes the block P of material formed by moving die 3 to be detached in case it should have happened to have adhered to die 3, while slide 2 continues its upwards motion. Piece P being freely disposed on fixed die 6 receives suction cup 31 which approaches the piece and comes to rest on it having first been displaced angularly through an L-shaped path before the suction cups axis is brought to line up with the axis of piece P, whereupon the cup lowers, covering the piece. At this instant cam 29 lowers plunger 28 of the valve and opens theV vacuum supply line 27, causing piece P to be sucked up and to remain attached to suction `cup 31, while line 26 to the compressed air tank is shut off.

After this, the suction cup is lifted up again and made to withdraw until it comes to a position immediately above conveyor 33 after which a further shift in the position of cam 29 causes plunger 28 to go back up again, shutting off 27 and opening up 26. The suction thereupon stops and the compressed air, entering through 26, piece P is made to fall on conveyor 33 which carries it away to another point Where it is further processed.

The cycle described above starts over again as a new block of material to be treated is fed to the dies.

FG. 2 shows a twin-mold press. Here, too, the slide 2 is given a reciprocating motion up and down and carries the moving dies 3 which are supported by supports 4 to which they are fastened by means of plates or platens 25.

The two fixed or stationary dies 6 are anchored to the body 8 of the machine by means of two supporting plates 7. To slide 2 is fixed the air cylinder 9 having a compressed air inlet 10 a compressed air outlet 11. Plunger 12 carries, fixed to rod 13 the supporting plate 14 for the two trimming rings 15 located around the outsides of each of the two moving dies 3.

Said trimming rings 15 are indicated by solid lines in their rest position, corresponding to the extreme upper position of the stroke of pneumatic plunger 12. Immediately after the moulding stroke, accompanied by the expulsion of all the excess soap from dies 3 and 6, support 14 moves to the position shown at 16 in dotted lines, corresponding to the lower end of the stroke of pneumatic plunger 12.

In this position the trimming rings 15 pass beyond the lines at which the two upper and lower dies match up and guarantee complete cutting of the excess soap expelled from the dies. In order to ensure that the trimming rings 15 return at maximum speed, pneumatic plunger 12 can be made to return to its rest position either by a spring 13 FIG. l or by reversing the air inlet and outlet 1t) and 11 using well-known means. In this way, by reversing the flow of compressed air, the motion of pneumatic plunger 12 is very rapidly reversed. In such a case, as shown in FIG. 2, suitable means are provided to give proper seal to the rods of the pneumatic plungers 12. The simultaneous use of both spring 13 combined With the reversal in the fiow of air through openings 10 and 11 is also taken into consideration.

Air cylinders 17 are built into platens 25 which carry the moving dies 3, said cylinders operating the ejectors 20. Each plunger has its own rod 19 connected with an ejector 20 housed in each moving die.

The rest position for ejectors 20 is provided by springs 21 suitably calibrated and arranged in position in the lower parts of the air cylinders 17.

As already mentioned, by means of a set of mechanisms and electropneumatic devices of known type and any of which may be used, an automatic sequence of events is controlled and actuated automatically, consisting in the placing of the piece to be molded between the open dies 3 and 6, the lowering of slide 2 to close the dies, the shift in position of plunger 12 which brings down the trimming rings 15, the actuation of the ejectors 20 and the advancement of the arm carrying the suckers, or suction cups (not shown in FIG. 2) to remove the stamped pieces from the dies and deposit them on their respective conveyor belts.

What I claim is:

1. A device of the kind described comprising at least one mold having a stationary die member and a movable die member, a slide carrying said movable die member to move same into and out of engagement with said stationary die member, a trimming member mounted on one of said die members for movement with respect thereto to trim excess material expressed from said mold, ejector means disposed in said movable die member to eject a molded article molded by said mold, uid means operatively connected to said trimming member and said ejector means to operate the same sequentially whereby the trimming member is caused to trim off the expressed material after the engagement of the die members and the ejector means is caused to eject the article at the instant the movable die member is moved out of engagement with the stationary die member, engaging means movable into a position to engage said molded article after being ejected from said movable die member, said engaging means after engaging said molded article being movable to another position to deposit said molded article onto a conveying means to carry said molded article to a position remote therefrom, and means operatively connected to said engaging means to cause same to engage said molded article as well as to move said engaging means into said engagement position and said depositing position.

2. A device according to claim 1 in which said trimming member is movably mounted on said movable die member.

3. A device according to claim 1 in which said engaging means include a suction cup having a configuration similar to that of said die members, said means operatively connected to said engaging means to cause same to engage said molded article comprise vacuum means and a cam operated piston to maintain said suction cup in engagement with said molded article through said vacuum means.

4. A device according to claim 3 in which said means to move said engaging means into said engaging position and said depositing position comprise a cam operated swing arm connected to said suction cup, and compressed air means connected to said suction cup through said cam operated piston to release said molded article from said suction cup to deposit same onto said conveying means.

5. A device according to claim 1 in which said ejector means is disposed in the substantial .center of said movable die member.

6. A device according to claim 1 in which said device comprises another mold similar to said rst mentioned mold and being spaced therefrom, and another trimming member and said irst mentioned trimming member being mounted in common and movable in common by said nid means operatively connected thereto with respect to movable die member of said molds.

References Cited in the le of this patent UNITED STATES PATENTS 257,030 Ley Apr. 25, 1882 359,637 Schuberth Mar. 22, 1887 673,847 Ruckl May 7, 1901 1,959,512 Wall et al May 22, 1934 2,635,289 Owens Apr. 2l, 1953 2,706,843 Davis Apr. 26, 1955 2,953,814 Mumford Sept. 27, 1960 2,984,888 Collens May 23, 1961 3,005,234 Oriani et al. Oct. 24, 1961 3,020,594 Malgowski Feb. 13, 1962 

1. A DEVICE OF THE KIND DESCRIBED COMPRISING AT LEAST ONE MOLD HAVING A STATIONARY DIE MEMBER AND A MOVABLE DIE MEMBER, A SLIDE CARRYING SAID MOVABLE DIE MEMBER TO MOVE SAME INTO AND OUT OF ENGAGEMENT WITH SAID STATIONARY DIE MEMBER, A TRIMMING MEMBER MOUNTED ON ONE OF SAID DIE MEMBERS FOR MOVEMENT WITH RESPECT THERETO TO TRIM EXCESS MATERIAL EXPRESSED FROM SAID MOLD, EJECTOR MEANS DISPOSED IN SAID MOVABLE DIE MEMBER TO EJECT A MOLDED ARTICLE MOLDED BY SAID MOLD, FLUID MEANS OPERATIVELY CONNECTED TO SAID TRIMMING MEMBER AND SAID EJECTOR MEANS TO OPERATE THE SAME SEQUENTIALLY WHEREBY THE TRIMMING MEMBER IS CAUSED TO TRIM OFF THE EXPRESSED MATERIAL AFTER THE ENGAGEMENT OF THE DIE MEMBERS AND THE 